Not really sure about ART pipes in your area, you would have to check your local laws. But it does replace the cat but they have the ability to be installed without have a CEL.

Spacer and ART pipes would be your best bang for the buck performance combo for sure, you will get a nice gain from that combo. If you are pure performance the stock intake with ztube would be your best bet (there is a nice sticky in the intake forum with most intakes dyno performances). I would do your stock intake, ztube, spacer, art pipes, and whatever exhaust you choose (choosing by the tone you like would be the best bet even over pure hp) and then you are pretty much ready for an osiris tune to maximize your performance mods.

As far as ART performance you can search up the main thread on them, there are a lot of dynos from motordyne and individual members to give you an idea of gains to expect. Same thing for the spacer.

 

As stated, Motordyne ART pipes paired to the Motordyne VQ system. That set-up will get meet your criteria's while sacrificing just a few HP at the top-end.

Since your replacing the OEM cats, a tune (Osiris) will be needed to maximize the full potential.

 

This has been very eye opening and informative guys. Thanks a lot for the help. I think Ill go for ART pipes & spacer, barring any legal issues. Wouldnt even have thought about it without G35D. Special thanks to Xet and Jairen. Cheers guys.

 

If you have no budget concerns, MD's TDX v2 and ART Pipe combo is dyno proven the most gains. See their dyno sheet on their site, http://www.motordyneengineering.com/...pID=7&CDpath=0.

If legal issues are a concern, idk what to say other than, there's TONS of us running ART Pipes and the TDX v2 (for decibel level issues) in California, where the fines and troubles are a lot more, I'm sure, than in Ohio. Just be aware when to keep your shifts under 2k-2.5k so the fumes and noise aren't big issues/attractors.

 

I dont know what you guys are talking about how the nismo doesnt make power?

I have it and paired up with a few other mods.. the car put 258whp baseline.
mods are just berk hfc, 5/16th spacer, ztube. Dont see how hfc and a spacer could put down that amount. A stock non revup only puts 225 to 230whp on a dynojet. Somehow i gained about 25-30 more. After a tune it made 265whp. Just my two cent.

In addition to that, going from a 2.25'' piping to a 3'' piping makes a difference.

 

Maybe I am doing it wrong... I have the same thing you do minus the Berk and don't really feel a difference.

 

Nah, you're normal. Even the best exhausts struggle to put out ~10whp, nismo likely makes even less. But without doing all of your mods all at once and getting tuned at the same time it is very hard to feel a big difference compared to modding piece by piece.

 

^-- that is pretty much on point.. I didn't feel a thing when I installed the exhaust. Even when I had it paired up with the 5/16th spacer and ztube... Still nothing, wasnt till I added the berk hfc and m2performance hr y-pipe that I felt more of an ummpfff. After tune the gradually pulls harder.

 

I wouldn't get ART pipes before an aftermarket exhaust. I did that and regret it looking back, because:

1. You'll have rasp.
2. At least on my car, I didn't notice a huge jump in power until I added the exhaust. It seems like the stock one is too restrictive to take advantage of the full potential from the ART pipes.

 

Look up the invidia gemini not to loud until you step on it but when driving normal its deep and sexy .....

 

Could you guys give any insight on how the performance of a high-flow cat compares to ART pipes? And do I need two cats / one for each side? What exactly does a Y-pipe replace? (I keep seeing these referred to)

 

check the art thread, there are threads comparing test pipes dyno to art pipes dyno before and after.